doc: Update testing.txt

Author: stahta01

testing.txt

@@ -4,6 +4,7 @@ The asm code at https://github.com/tomctomc/coco_roms was used to test:
   vasm6809_oldstyle
   toolshed's mamou
   dasmfw                re-test needed on disk11.rom generated by coco_roms
+  toolshed's dis68
 
 Used 6809_ide_xroar from https://github.com/n6il/eou_ide/releases to test:
   xroar
@@ -13,7 +14,7 @@ Used https://github.com/stahta01/xroar_coco_examples to test:
   toolshed's decb       Tested 2025-06-03
   xroar                 Tested 2025-06-03
 
-Used https://github.com/stahta01/nitros9 to test: 
-  toolshed's os9        Tested 2025-06-03 
-  lwtools's lwasm       Tested 2025-06-03
-  xroar                 Tested 2025-06-03
+Used https://github.com/stahta01/nitros9 to test:
+  toolshed's os9        Tested 2025-09-01
+  lwtools's lwasm       Tested 2025-09-01
+  xroar                 Tested 2025-09-01